St. David, IL has a population of 697 and is the 17,506th largest city in the United States. The population density is 2,330 per sq mi which is 948% higher than the Illinois average and 2472% higher than the national average. The median age in St. David is 43 which is approximately 16% higher than the Illinois average of 37. In St. David, 56% of the population over 15 years of age are married, 97% speak English and 0% speak Spanish. 78% of St. David residents were born in Illinois, 19% were born out of state, 0% were born outside of the United States and 3% were foreign born.